In general, a “portable terminal” may refer to a device that allows a communication function, a schedule management function, a multimedia file reproducing function, a game function, an electronic diary function, and so forth, while a user is carrying the portable terminal, and a mobile communication terminal is an example of such a portable terminal. Such a mobile communication terminal is installed with various functions, ranging from a simple voice communication function to the above-mentioned schedule management, multimedia file reproducing, game functions, and such. Recently, it has become possible for such a mobile communication terminal to receive or transmit services, such as digital multimedia broadcasting and large information files, that are provided in real time.
Such a portable terminal has a case, within which various circuit devices are arranged, and a cover member assembled to an opened side of the case in such a manner that the case and the cover member form a housing. The case may be formed with openings on the opposite side of the opened side or on a lateral side, such that input/output devices, such as a keypad and a display module, can be exposed as desired.
In order to minimize interference phenomena caused by a metallic material in connection with the actions of various circuit devices including an antenna device, the housings of portable terminals have been typically formed from a synthetic resin material. Recently, however, those housings are sometimes fabricated from a metallic material. This is because, due to the development of electronic communication technologies, the normal operations of the antenna device and the circuit devices are not significantly affected by an interference phenomenon, even if such a phenomenon occurs between one or more circuit devices and a metallic housing.
However, because it is advantageous to fabricate housings from a synthetic resin in order to diversify the shapes and colors of portable terminals, housings are manufactured by using a synthetic resin material and a metallic material in combination.
In addition, for a sliding-type terminal, it is advantageous to use a metallic material so as to secure structural strength because a pair of housings are slidably coupled to each other. It is possible to fabricate a sliding module and housings of a portable terminal separately and then to assemble them. In such a situation, however, the thickness of the resultant terminal is increased. Therefore, efforts are being continuously made for reducing the thickness of terminals, specifically the housings of the terminals, by forming slidable coupling parts on the housings of a terminal, and fabricating the slidable coupling parts from a metallic material.
However, if housings are fabricated from a synthetic resin material and a metallic material in combination, there is a disadvantage in that the adjoining parts between the synthetic resin material and the metallic material are frail to external impacts. That is, if external impacts are applied to the housings, the impacts will be concentrated to the adjoining parts between the synthetic resin material and the metallic material, and thus the adjoining parts may be readily fractured.